Dear all, More and more we are using purchased Switch Mode Power Supplies for our equipment. The SMPS manufacturer delivers us then a CB report of the SMPS in order to make the test report of the equipment for the safety approval ( CEBEC and UL).
Up to now we always performed the heating test of the purchased SMPS: we measured the temperature of the critical components on the smps itself to see if they remain under the safe limit. We are now having a problem with a particular power supply. The 600 W power supply is a fully closed metal box with cooling fans on the front. When we open it and add thermocouples on the PFC part of the power supply, the PFC fails. This is probably due to the fact that we are coupling in some wrong signals on a feedback circuit. We tried it several times with the same result: failure of the PFC part of the SMPS. My question is: is the heating test really necessary? The CB report states that the Power Supply was investigated in a maximum ambient of 50°C. Should it not be sufficiant to measure the temperature of the environment and if this temperature remains down the 50°C in all circumstances, can't we conclude that the heating test is not necessary and that we don't have to open the smps in order to fix the themocouples? best regards, Van Compernolle Eric Reliability Manager Barco Projection System Noordlaan 5 Industriezone B-8520 Kuurne Belgium Tel. +32(0)56 36 82 11 Fax.+32(0)56 36 83 55 E-mail: [email protected] . - - - - - - - DISCLAIMER - - - - - - - - Unless indicated otherwise, the information contained in this message is privileged and confidential, and is intended only for the use of the addressee(s) named above and others who have been specifically authorized to receive it. If you are not the intended recipient, you are hereby notified that any dissemination, distribution or copying of this message and/or attachments is strictly prohibited. The company accepts no liability for any damage caused by any virus transmitted by this email. Furthermore, the company does not warrant a proper and complete transmission of this information, nor does it accept liability for any delays. If you have received this message in error, please contact the sender and delete the message. Thank you.
